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Spatial Distribution and Diversity of Marine Zooplankton Adjacent to the St. Martin's Island, Bangladesh

Alam Md. Jobaer, Kamal A. S. M. Maksud, Ahmed Md. Kawser, Khondker Moniruzzaman, Fayyaz Rafid

Journal of Ecological Engineering

2022

Vol. 23, nr 10

154--163

Bangladesh, a country that lies on the north shores of the Bay of Bengal, has been blessed with a plethora of natural resources. St. Martin’s Island, the only coral-bearing island in Bangladesh, is undoubtedly regarded as one of the most prized possessions. It is rich in biodiversity, but truly scientific information on it is lacking. In the present investigation, 14 stations adjacent to St. Martin’s Island within the Bay of Bengal were sampled for determining the composition, spatial distribution, species richness, and diversity of pelagic zooplankton. Samples were collected in the pre-monsoon hot season. From the community of zooplankton, 34 species were reported. Most of the species belonged to copepods. Besides, Polychaeta and Cirripedia were also present in the community. The most significant species belonged to Oithona, Canthocalanus, Balanus, Euterpina, and Microsetella. Total zooplankton standing crop varied from 45,000–125,000 ind/m3 and the highest number of species (8) were observed at station 7. Strong variability in the distribution of species was observed in the studied stations. The number of genera collected at each station varied from 4–8. Data on species richness (Df) varied from 1.30–3.04 and that of the Shannon-Wiener Index (H) from 1.33–1.93. The species composition of zooplankton and the species richness and the diversity index of the population was comparable to the other studies carried out in the Central and Western Bay of Bengal.

Seasonal influence of physico-chemical parameters on phytoplankton diversity, community structure and abundance at Parangipettai coastal waters, Bay of Bengal, South East Coast of India

Manigandan V., Yosuva M., Saravanakumar A., Machendiranathan M.

Oceanologia

2018

No. 60 (2)

114--127

The present investigation studied the seasonal variation between physico-chemical parameters and phytoplankton diversity, community structure and abundance; quantitative samples were collected on a monthly basis from April 2015 to March 2016 at Parangipettai coast, the Bay of Bengal (BOB). Statistical analyses were performed on physico-chemical parameters such as salinity, dissolved oxygen (DO), pH, temperature, nitrate, nitrite, silicate, and inorganic phosphate (IP). The significant (P < 0.0005) variation among seasons as well as a high influence of these parameters was observed on phytoplankton productivity. Totally, 117 species were identified, belonging to five different classes, Coscinodiscophyceae (62%), Bacillariophyceae (17%), Fragilariophyceae (8%), Dinophyceae (8%) and Cyanophyceae (5%). Throughout the study period, the occurrence of most dominant species was observed from class Coscinodiscophyceae and Bacillariophyceae. The phytoplankton species also showed significant changes according to seasonal variations as well as the nutrient availability. Phytoplankton attained their maximum population density during premonsoon; whereas minimum population was observed during monsoon. The performed statistical analysis on phytoplankton species, the Shannon & Wiener diversity index was found to be higher during postmonsoon and lower during monsoon season. The Canonical Correspondence Analysis (CCA) was used, to find out the seasonal relationship between phytoplankton and physicochemical parameters. Hence, the executed CCA results revealed that temperature, salinity, silicate, DO and IP have a higher influence on phytoplankton abundance.

Pasożyty jelitowe młodocianych ryb łososiowatych zlewni dolnej Odry i środkowego Niemna

Pilecka-Rapacz M., Kazlauskiene N., Kesminas V, Czerniawski R.

Rocznik Ochrona Środowiska

2013

Tom 15, cz. 1

671--682

Atlantic salmon died out in Poland during the 1980s. The current population was recreated with Latvian salmon and now forms part of the southern Baltic cohort. Polish sea trout and brown trout come from the home cohort, but have survived only with regular restocking. In Lithuania, all the salmonides are from the home cohort and have not been restocked. The aim of this study was to compare parasitic invasion in juvenile salmonides that come from Poland and Lithuania. The juvenile salmonides in this study came from the lower Oder River basin and from the middle of the Neman River. 153 fish were caught using electrofishing from 2004 to 2006. The salmonides in the Oder had been artificially restocked and those in the Neman were wild. 33 salmon, 58 sea trout and 24 brown trout came from small tributaries of the Oder; 22 salmon, 5 sea trout and 11 brown trout came from tributaries of the middle Neman River. The fish were either 0+, 1+, or 2+ years old. Their size was characteristic for their species at that age, which suggested that they were in good condition. Our examination found 6 species of parasites from 3 taxa: Cestoda – Cyathocephalus truncates; Nematoda – Cystidicoloides ephe¬meridarum and Raphidascaris acus; and Acanthocephala – Acantho¬cephalus lucii, A. anguillae and Metechinorhynchus truttae. We found all three taxa of parasites in all the salmonides that came from the tributaries of the Oder, but all three taxa were found only in salmon from the Neman tributaries. In sea trout and brown trout from tributaries of the Nemen River we found only Nematoda. The invasion frequency was much higher in salmonides that came from tributaries of the Oder River than in salmonides from tributaries of the Nemen River. In tributaries of the Oder River, 57.6% of the salmon, 62.1% of the sea trout, and 58.3% of the brown trout had parasites. In tributaries of the Nemen River, 27.3% of the salmon, 40% of the sea trout, and 36.4% of the brown trout had parasites. In salmonides from both rivers the most common parasites were C. ephemeridarum, M. truttae, and C. truncatus. The other species of parasites were found in very few cases. Older salmonides had greater numbers of parasites. Although the salmonides came from different rivers and had different origins, the species of parasites that they had were typical for their family. In conclusion, parasite invasion is similar in salmonides both from the lower Oder River basin and from the middle of the Neman River.